Akira, the Song Dragon

Tongues. Akira is permanently under the effect of the Tongues spell.

Legendary Resistance (3/day). If Akira fails a saving throw, she can choose to succeed instead.

Polymorph. As an action, Akira the Song Dragon can transform into her human female form keeping only her Charisma, Intelligence and Wisdom scores, while the rest of her scores becomes that of Akira the Seer.

Multiattack. Akira uses her Frightful Presence and makes one bite attack and two claw attacks. She can forgo her bite attack to make a tail attack.

Bite. Melee Weapon Attack: +10 to hit, reach 10 ft., 1 target. Hit: 14 (2d8 + 5) piercing damage. 

Claw. Melee Weapon Attack: +10 to hit, reach 5 ft., 1 target. Hit: 12 (2d6 + 5) slashing damage. 

Tail. Melee Weapon Attack: +10 to hit, reach 10 ft., 1 target. Hit: 11 (1d10 + 5) bludgeoning damage. 

Frightful Presence. Each creature of Akira's choice that is within 120 feet of her and aware of her must succeed on a DC 16 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to Akira's Frightful Presence for the next 24 hours.

Breath Weapons (Recharge 5–6). Akira uses one of the following breath weapons.

Lightning Breath. Akira exhales lightning in a 60-foot line that is 5 feet wide. Each creature in that line must make a DC 16 Dexterity saving throw, taking 24 (4d8) lightning damage on a failed save, or half as much damage on a successful one.

Slowing Breath. Akira exhales gas in a 60-foot cone. Each creature in that area must succeed on a DC 16 Constitution saving throw. On a failed save, the creature can't use reactions, its speed is halved, and it can't make more than one attack on its turn. In addition, the creature can use either an action or a bonus action on its turn, but not both. These effects last for 1 minute. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself with a successful save.

Akira can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Akira regains spent legendary actions at the start of its turn.

Detect. Akira makes a Wisdom (Perception) check.

Tail Attack. Akira makes a tail attack.

Wing Attack (Costs 2 Actions). Akira beats her wings. Each creature within 10 feet of Akira must succeed on a DC 19 Dexterity saving throw or take 13 (2d6 + 5) bludgeoning damage and be knocked prone. Akira can then fly up to half of her flying speed.